Heating of fluids



Sept. 13, 1938. M. w. BARNES HEATING OF FLUIDS Filed Jan, 20, 1934INVENTOR MAR N W; BARNES g 5 TORNEY Patented Sept. 13,1938 I UNITEDSTATES PATENT OFFICE 2,129,900 HEATING or FLUIDS Marion W. Barnes,Chicago, Ill., assignor to Universal Oil Products Company, Chicago,111., a corporation of Delaware Application January 20, 1934, Serial No.707,535 3 Claims. (01:122-356) This invention particularly refers toimproveof the furnace is separated from combustion merits in the heatingof fluids which is particuzones 5 and 6 by relatively short suspendedwalls larly well adapted to subjecting hydrocarbon oils 1 and 1 wherebythe main furnace structure is to the high temperatures required fortheir pyrodivided into three separate heating zones 4, 5

5 lytic conversion, although it is not limited to such and 6. 5 use andmay be employed to advantage in the A plurality of suitable firingtunnels such as heatingof liquid, vapors and gases generally asindicated at 8 are provided at each end of the well a mixtur f th same,furnace and a. combustible fuel-air-mixture of I have previouslydisclosed an improved type any suitable form is supplied by means ofburnl0 of furnace for the heating of fluids having two ers 9 throughfiring compartment ill of tunnels 10 independently fired combustionzones each con- 8 to each of the combustion zones 5 and 6. Any tainingfluid conduits supplied predominantly desired portion of the airrequired for combuswith radiant heat, the heating conditions in each'tion as well as any desired quantity of excess air being independentlycontrolled, and having a, may be supplied to each of the combustionzones centrally located fluid heating zone separated through ducts IIand II' of firing tunnels 8 15 from each combustion zone by a bridgewall and which, in the case illustrated, are located respeccontaining afluid conduit around which the comtively' above and beneath firingcompartments l0. bustion gases from both combustion zones pass Excessair may also be admitted; when desired, in a downward direction therebysupplying fluid through firing tunnels l0.

heat thereto. The present invention embodies It will be noted that inthe furnace structure 20 improvements to this general type of furnacehere illustrated there are no obstructions in the structure, comprisinglocating the fluid heating direct path of flow of the combustion gasesfrom bank adjacent the roof of the furnace 'above firing tunnels 3 t0 tf u heating Z0118 Walls and at substantially right angles to the sourceof I and 'l' preferably extending only a relatively heat. I have foundthat this arrangement augshort distance below roof 2 sufllcient top o 25ments the natural draft conditions in the furthe sweep of hot combustiongases along the roof nace, since the movement of the gases through ofthe furnace to fluid heating zone 4 but not sufthe furnace due to thestack draft is in harmony ficient to obstruct or retard the free flow ofgases with the natural tendency of the heated gases to through thecombustion zones into the fluid heatrise. This largely eliminates eddycurrents and ng z e- It w ll also b t d t firing 30' the back-wash ofgases along the fluid conduit nels 8 are elevated, in the preferredembodiment and results in a more definite separation of radihereillustrated, sufficiently to prevent the sweep ant and convection heatthan in any other furof hot combustion gases along the fl 0f t nace ofthe so-called open radiant type. This furnace. In this mannerpredominantly'radiant eliminates any dangerous and excessive superimt ismpart d o t fluid Conduits along e 35 posing of convection and radiantheat in the fluid roof and floor of the combustion zones with a conduitslocated within the combustion zones and minimum of superimposedconvection heat. The permits better control of the heating conditionsgeneral direction of fiow'of the hot combustion in each of the threeheating zones. The improved gases from firing tunnels l0 throughcombustion 40 form of furnace of the present invention elimizones 5 and8 tofiuid heating zone 4 is indicated 40 nates expensive bridge wallconstruction, underby the arrows in the figure. The hot combusgroundflues and considerably decreases the tion a s m b th Combustion Zonescommihheight of the main furnace structure. gle within and beneath fluidheating zone 4 and The features of the present invention and their passupward therethrough to a suitable flue I2 advantages will be moreapparent with reference leading to a stack, not shown. to theaccompanying diagrammatic drawing and A fluid conduit l3 comprising, inthe case illusthe following description thereof, the single figuretrated, a sin l h ri o l row f horizon al y sof the drawing being across-sectional elevation posed tubes I4 is located adj the floor of ofone specific form of furnace embodied by the combustion zone 5 and asimilar fluid conduit 15,

present invention. also comprising, in the case illustrated, a single 50Referring to the drawing, the main furnace horizontal row ofhorizontally disposed tubes l4, structure comprises end walls I and l, aroof 2, is located adjacent the floor of combustion zone 6. a floor 3and side walls which do not appear in Another fluid conduit l6comprising, in the case the particular view shown. A centrally locatedillustrated, a single horizontal row of horizontally fluid heating zoneE extending-through the roof disposed tubes I4 is located adjacent theroof of 55 combustion zone 5 and a similar fluid conduit I! alsocomprising, in the case illustrated, a single horizontal row ofhorizontally disposed tubes I4 is located adjacent the rbof ofcombustion zone 6. Another fluid conduit l8 comprising a plurality ofhorizontally parallel rows of horizontally disposed tubes is locatedwithin fluid heating zone 4, Although not illustrated in the drawing,the tubes I4 of each of the banks l3, l5, l6, l1 and I8 extend acrossthe entire width of the various heating zones and terminate in suitableheaders or return bends, preferably located outside the heated zone. Itwill be understood that two or more rows of tubes may, when desired, beemployed in any or all of the fluid conduits l3, I5,- I 6 and I1although preferably when more than a single row is utilized the tubesare so spaced that the projected surface of each is exposed to directradiation from the flames and hot combustion gases in combustion zones 5and6. It is also within the scope of the invention, when desired, toeliminate the portions of fluid conduits I3 and l5 located beneath fluidheating zone 4 and indicated in the drawing at I3 and I5, respectively.Elimination of .these tubes will serve. to substantially increase theheat imparted to tube bank l8 and particularly the lower 2 or 3 rows ofthis bank.

As indicated by the arrows on the drawing, the oil or other fluid toibeheated enters the upper row of tubes in tube bank l8, flowing in seriesthrough adjacent tubes in the same row and through the adjacent rows oftubes in a general direction counter-current to the direction of flow ofcombustion gases through this zone of the furnace, emerging from thelower row of tubes in bank I 8 and entering the end tube of roof bank l1adjacent tube bank l8, flowing in series through adjacent tubes in bankIT in a general direction counter-current to the direction of flring,emerging from the end tube of bank I! adjacent the end wall of thefurnace and entering the last tube at the same end of floor bank l5,flowing in series through adjacent tubes in this bank in a generaldirection concurrent to the direction of firing, flowing then in seriesthrough adjacent tubes in rection countercurrent to the direction offiring, emerging from the end tube of bank l3 adjacent the other endwall of the furnace and entering the last tube at the same end of roofbank l6, flowing in series through adjacent tubes in this bank in ageneral direction concurrent to the direction of firing and beingdischarged from the end tube of bank I 6 adjacent bank I8 and from thefurnace.

This general type of flow wherein the same stream of fluid passesthrough the fluid conduits -in one combustion zone of the furnace andthen through the fluid conduits in the other combusthrough the end wallsfloor bank H in a general disuch as those containing a substantialproportion of materials within the boiling range of motor fuel, whereinitis desirable to first heat the distillate to the desired conversiontemperature and then to maintain the stream of heated distillate at ornear the maximum temperature previously attained for a predeterminedtime.

I claim as my invention:

1. In combination with a furnace having end walls, a roof and a floor,means forming a convection heating zone extending upwardly from a thecentral portion oi the furnace roof, heating tubes in said zone,.additional heating tubes in the end portions of the furnace proper onthe opposite sides of said zone, means for firin the furnace above thefloor in opposite directions substantially horizontally toward thecentral portion of the furnace, means for removing combustion gases fromthe convection heating zone, and means for passing fluid seriallythrough the tubes in said zone and in the furnace proper on the oppositesides of said zone.

2. In combination with a furnace having end walls, a roof and a floor,means for firing the furnace through the end walls and above the floorin opposite, substantially horizontal directions toward the centralportion of the furnace, means forming an outlet duct for combustiongases through the central portion of the furnace roof, heating tubes insaid duct, additional heating tubes in the furnace proper on both sidesof said duct, and disposed substantially at right angles to thedirection of flring, and means for a passing fluid serially through thefirst-mentioned furnace floor, said roof tubes 'and additional tubesbeing disposed substantially at right angles to the direction of firing,and means for passing fluid serially through the first-mentioned tubes,the roof tubes and said additional tubes.

MARION w. BAnNns.

